In order to explore the potential productivity of rice under the condition of planting green manure Lathyrus sativus and reducing nitrogen application, we set up six treatments: winter fallow + no fertilization (NF), green manure L. sativus + no nitrogen fertilizer (GM), winter fallow + 100% nitrogen fertilizer (CK), green manure L. sativus + 80% nitrogen fertilizer (GM + 80%N), green manure L. sativus + 70% nitrogen fertilizer (GM + 70%N), green manure L. sativus + 60% nitrogen fertilizer (GM + 60%N), and studied the effects of different treatments on growth, nutrient absorption and yield of rice. The results showed that: (1) compared with CK, turning green manure L. sativus and reducing nitrogen application could significantly improve the plant height, tiller number and dry matter accumulation of rice, among which GM + 70%N fertilization treatment had the most obvious effect. (2) Under the GM + 70%N fertilization treatment, the plant height and effective tiller number of rice at different growth stages increased 13.32%-15.73% and 33.98%-59.47%, respectively, compared with the control conventional fertilization (100%N), and the dry matter accumulation increased 23.19%-144.18%, and the increasing rate decreased with the advance of growth stage. (3) The yield of rice was increased under the treatment of turning green manure L. sativus and reducing nitrogen fertilizer, The GM + 70%N and GM + 80%N treatments significantly increased the yield of rice by 13.84% and 7.25%, respectively, and the nutrient absorption of rice plants and grains was more comprehensive under the GM + 70%N treatment. The study found that planting L. sativus and reducing the application of appropriate amount of nitrogen fertilizer can effectively promote the growth of rice and the absorption and accumulation of nutrients, and significantly improve the yield of rice. It shows that turning green manure L. sativus can replace 30%-40% of the nitrogen fertilizer application in the rice field, and can avoid the prosperity of rice and achieve high yield of paddy rice, which is a better tillage measure for rice planting in Sichuan.